FM放送とマルチパスを適応フィルタで極めてみた / Solving multipath distortion of FM broadcast by adaptive filters

さくらの夕べ 研究所ナイト 2020年1月16日 発表原稿

Transcript

1. FM์ૹͱϚϧνύεΛ
   దԠϑΟϧλͰۃΊͯΈͨ
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 1
   

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2. Kenji Rikitake
   Γ͖͚ͨ ͚Μ͡
   ྗ෢ ݈࣍
   16-JAN-2020
   ͘͞Βͷ༦΂ ݚڀॴφΠτ
   Sakura Internet Fukuoka Office
   Fukuoka City, Fukuoka, Japan
   @jj1bdx
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 2
   

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3. ٕज़࢜ʢ৘ใ޻ֶ෦໳ʣ
   ྗ෢݈ٕ࣍ज़࢜ࣄ຿ॴ ॴ௕
   ϖύϘݚڀॴ ٬һݚڀһ
   ΞϚνϡΞແઢྺ 44೥
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 3
   

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4. FM์ૹ͸ϚϧνύεׯবͰԻ͕Ԛ͘ͳΔ
   • ෳ਺ܦ࿏ͷ൓ࣹ೾͕߹੒͞Εͯ೾ܗ͕ཚΕΔ
   • ৼ෯Ұఆͷ͸͕ͣৼ෯͕มԽ͢Δ
   • ৼ෯ͷมԽ͸ଈࠁҐ૬ͷ࿪Έ
   • Ґ૬͕࿪Ήͱͱͯ΋ෆշͳԻ͕͢Δ
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 4
   

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5. Kenji Rikitake / Sakura Lab Night 16-JAN-2020 5
   

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6. ΍ͬͯ͸͍͚ͳ͍͜ͱ
   ৼ෯Ұఆʹڧ੍ͯ͠΋࿪Έ͸ফ͑ͳ͍!
   Ϧϛολ͸ແҙຯ
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 6
   

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7. ݪཧʹ஧࣮ʹߟ͑Δ
   ෳ਺ͷ஗Ԇ৴߸͕ׯব͍ͯ͠ΔͷͰ͋Ε͹ɺ
   ͦͷׯবͷٯԋࢉΛߦͬͯऔΓআ͘
   Kenji Rikitake / Sakura Lab Night 16-JAN-2020 7
   

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8. Kenji Rikitake / Sakura Lab Night 16-JAN-2020 8
   

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9. Kenji Rikitake / Sakura Lab Night 16-JAN-2020 9
   

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10. ϚϧνύεׯবҎલͷঢ়ଶʹ໭͢ʹ͸
    • ஗ԆͱՃࢉ͸FIRϑΟϧλͰ࣮ݱͰ͖Δ
    • ൓ࣹ೾ͷٯԋࢉΛ΍Ε͹Α͍
    • LMS๏ͰదԠϑΟϧλ܎਺Λܾఆ
    • ܎਺ͷܾఆ৚݅: ৼ෯Ұఆʹ໭͢
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 10
    

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11. దԠϑΟϧλͷ࣮૷ྫ
    1980೥୅ʹ࿦จൃද 1
    ྛً඙ࢯʹΑΔFMDDC-3
    ྗ෢ʹΑΔairspy-fmradion
    1 ๬݄ ޹ࢤ, Ӌௗ ޫढ़, దԠσΟδλϧϑΟϧλʹΑΔFMϚϧνύεͻͣΈࣗಈআڈͷҰํࣜ, ςϨϏδϣϯֶձࢽ,
    1985, 39 ר, 3 ߸, p. 228-234, ެ։೔ 2011/03/14, Online ISSN 1884-9652, Print ISSN 0386-6831, h>ps:/
    /doi.org/
    10.3169/itej1978.39.228, h>ps:/
    /www.jstage.jst.go.jp/arHcle/itej1978/39/3/39_3_228/_arHcle/-char/ja
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 11
    

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12. దԠϑΟϧλΛVOLKͰ࠷దԽ
    • ίϯύΠϥʹ೚ͤΔͱݶք͕͋Δ
    • VOLK: SIMD໋ྩద༻ϥΠϒϥϦ h-p:/
    /libvolk.org/
    • ϧʔϓͰॲཧͰ͖Δ΋ͷΛSIMDʹ͢Δ
    • ੵ࿨ԋࢉ͸6ഒͷߴ଎Խ2
    2 Kaby Lake, volk_32fc_x2_dot_prod_32fc(), generic -> u_avx_fma
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 12
    

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13. #if !VOLK
    for (unsigned int i = 0;
    i < m_filter_order; i++) {
    output += m_state[i] * m_coeff[i];
    }
    #else // VOLK
    volk_32fc_x2_dot_prod_32fc(&output,
    m_state.data(), m_coeff.data(),
    m_filter_order);
    #endif // VOLK
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 13
    

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14. ྗ෢ͷ࣮૷: airspy-fmradion
    Airspy HF+΍RTL-SDRͱMac΍Raspberry Piͷ૊Έ߹ΘͤͰಈ࡞
    ߴڃFMνϡʔφʹඖఢ
    FMԕڑ཭ड৴ʹ΋ޮՌ
    ઈࢍ։ൃத
    h"ps:/
    /github.com/jj1bdx/airspy-fmradion
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 14
    

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15. Thank you
    Graphics credits:
    • Audacity simula.on: Kenji Rikitake
    • Mul.path impulse response: I, Cantalamessa, h>ps:/
    /
    commons.wikimedia.org/wiki/
    File:Mul.path_impulse_response.png from Wikimedia Commons,
    licensed CC BY 2.5
    Kenji Rikitake / Sakura Lab Night 16-JAN-2020 15
    

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